Synthesis, Characterization, and Applications of Carbon Nanotubes Functionalized with Magnetic Nanoparticles

Carbon nanotubes (CNTs) and magnetic nanoparticles (MNPs) are amalgamated to produce a new type of sensing ink. The combined properties of CNTs and MNPs also justify their use as additives in composite materials. These developments open new windows for nanotechnology applications. This chapter elucidates the methods of synthesizing MNPs, using them to functionalize and chaperone CNTs, and the capabilities of these MNP-CNT conjugates. Section 2.1 provides a general introduction to CNTs (Section 2.1.1) and MNPs (Section 2.1.2). Different ways of functionalizing CNTs are discussed in Section 2.2. The process of covalent functionalization of CNTs when co-precipitated MNPs are attached to the surfaces of nanotubes is explained in Section 2.3, including a detailed methodology (Section 2.3.1) and the formulation of a magnetoresponsive and electrically conductive ink (Section 2.3.2). Different methods of noncovalent functionalization of CNTs are discussed in Section 2.4 with an emphasis on electroless plating of CNTs (Section 2.4.1), entanglement of MNPs with CNTs (Section 2.4.3), and an example of how to print sensors (Section 2.4.4). Endohedral functionalization of CNTs is described in Section 2.5 with future perspectives elucidated in Section 2.6.